Partners at Piper Rudnick and the British law firm DLA agreed over the weekend to a merger, a move that will create one of the world’s 10 largest corporate law firms.

With 2,700 lawyers and estimated revenue of more than $1.2 billion worldwide, the firm will be called DLA Piper Rudnick Gray Cary.

Both DLA and Piper have grown significantly in the last five years through a rapid-fire series of mergers and acquisitions, but this represents a major international jump for Piper, which through the combination will gain offices in 18 countries throughout Europe and Asia.

This is the second major merger announced this fall by Piper Rudnick, itself the product of the 1999 combination of Baltimore’s Piper & Marbury and Chicago firm Rudnick & Wolfe. In October, Piper agreed to a merger with California’s Gray Cary Ware & Freidenrich, a 380-lawyer firm with a strong technology practice.

Similarly, DLA was created in the mid-1990s when two regional law firms linked up to create a single firm that at the time had 350 lawyers in six U.K. offices.

Legal Times reported in October on the DLA-Piper merger and the Piper combination with Gray Cary, both of which will be effective Jan. 1.

The new firm, which says it wants to be a “top five global” law firm, will be led by Piper Rudnick’s co-chairs, Francis Burch Jr. and Lee Miller, and DLA’s managing partner, Nigel Knowles. The three will all serve as joint CEOs. The firm will be chaired by Piper partner and former Senate Majority Leader George Mitchell (D-Maine).